ASSESSING AIR INFILTRATION RATES OF AGRICULTURAL USE VENTILATION CURTAINS

2001 ◽  
Vol 17 (4) ◽  
Author(s):  
S. J. Hoff
Keyword(s):  
Infiltration Rates ◽  
Air Infiltration ◽  
Agricultural Use

scholarly journals Swine Finishing Room Air Infiltration: Part 1. Quantification and Prediction

2018 ◽  
Vol 34 (2) ◽  
pp. 413-424
Author(s):  
H T Jadhav ◽  
S J Hoff ◽  
J D Harmon ◽  
Igancio Alvarez ◽  
D S Andersen ◽  
...  
Keyword(s):  
Sea Level ◽  
Power Law ◽  
Pressure Difference ◽  
Construction Material ◽  
Weather Conditions ◽  
Infiltration Rate ◽  
Mechanically Ventilated ◽  
Infiltration Rates ◽  
Air Infiltration ◽  
Single Room

Abstract. Air infiltration through unplanned inlets is an integral component of any ventilation process. Air infiltration affects the quality of the room environment and can also increase winter heating costs. Precise data on air infiltration is very important in the design of animal room ventilation systems. Nineteen mechanically ventilated (negative pressure type) swine finishing rooms in Iowa were tested for their air infiltration potential. Using the data of 17 rooms, air infiltration rate through the whole room (i.e., total air infiltration, It), curtains (Ic), fans (If), and net building shell (other components, Io) were quantified. Power law equations were developed for infiltration prediction of different room configurations grouped on the basis of their construction style, age, ceiling material, curtain perimeter, and fan backdraft shutter area. All power law models reported in this study were adjusted to predict standard (sea level) infiltration rates. At 20 Pa pressure difference across the room envelope, the predicted standard It infiltration rate for the 17 rooms was 5.96±1.49 air changes per hour (ach); whereas, the predicted standard Ic, If, and Io infiltration rates were 1.49 ±1.00 ach (about 25% of It), 1.52 ±1.38 ach (about 26% of It) and 2.90 ±1.42 ach (about 49% of It), respectively. The standard It infiltration rate trended lower for rooms (n=8) from single room layout barns (5.85 ±1.66 at 20 Pa), rooms (n=8) having a non-metal ceiling (5.85 ±2.15 at 20 Pa), and rooms (n=8) aged = 13 years (5.85 ±2.15 at 20 Pa). The infiltration resistances, calculated using standard sea level infiltration rates, indicated that the curtain, fan, and other infiltration areas of swine finishing rooms changes with barn layout, age, construction material, and pressure difference. Methodology to convert measured infiltration rates to standard sea level weather conditions and to any desired room location was included. Keywords: Infiltration, Swine finishing Barns, Swine finishing rooms, Infiltration prediction, Infiltration quantification, Ventilation.

scholarly journals Evaluating methods for estimating whole house air infiltration rates in summer: implications for overheating and indoor air quality

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ben M. Roberts ◽  
David Allinson ◽  
Kevin J. Lomas
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Infiltration Rate ◽  
Estimation Methods ◽  
Tracer Gas ◽  
Content Type ◽  
Infiltration Rates ◽  
Air Infiltration ◽  
Fan Pressurisation

PurposeAccurate values for infiltration rate are important to reliably estimate heat losses from buildings. Infiltration rate is rarely measured directly, and instead is usually estimated using algorithms or data from fan pressurisation tests. However, there is growing evidence that the commonly used methods for estimating infiltration rate are inaccurate in UK dwellings. Furthermore, most prior research was conducted during the winter season or relies on single measurements in each dwelling. Infiltration rates also affect the likelihood and severity of summertime overheating. The purpose of this work is to measure infiltration rates in summer, to compare this to different infiltration estimation methods, and to quantify the differences.Design/methodology/approachFifteen whole house tracer gas tests were undertaken in the same test house during spring and summer to measure the whole building infiltration rate. Eleven infiltration estimation methods were used to predict infiltration rate, and these were compared to the measured values. Most, but not all, infiltration estimation methods relied on data from fan pressurisation (blower door) tests. A further four tracer gas tests were also done with trickle vents open to allow for comment on indoor air quality, but not compared to infiltration estimation methods.FindingsThe eleven estimation methods predicted infiltration rates between 64 and 208% higher than measured. The ASHRAE Enhanced derived infiltration rate (0.41 ach) was closest to the measured value of 0.25 ach, but still significantly different. The infiltration rate predicted by the “divide-by-20” rule of thumb, which is commonly used in the UK, was second furthest from the measured value at 0.73 ach. Indoor air quality is likely to be unsatisfactory in summer when windows are closed, even if trickle vents are open.Practical implicationsThe findings have implications for those using dynamic thermal modelling to predict summertime overheating who, in the absence of a directly measured value for infiltration rate (i.e. by tracer gas), currently commonly use infiltration estimation methods such as the “divide-by-20” rule. Therefore, infiltration may be overestimated resulting in overheating risk and indoor air quality being incorrectly predicted.Originality/valueDirect measurement of air infiltration rate is rare, especially multiple tests in a single home. Past measurements have invariably focused on the winter heating season. This work is original in that the tracer gas technique used to measure infiltration rate many times in a single dwelling during the summer. This work is also original in that it quantifies both the infiltration rate and its variability, and compares these to values produced by eleven infiltration estimation methods.

scholarly journals Home Energy Efficiency and Subjective Health in Greater London

2021 ◽  
Author(s):  
P. Symonds ◽  
N. Verschoor ◽  
Z. Chalabi ◽  
J. Taylor ◽  
M. Davies
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Positive Association ◽  
Significant Positive Association ◽  
Health And Wellbeing ◽  
Infiltration Rates ◽  
Air Infiltration ◽  
Reported Health ◽  
The Uk ◽  
The Relationship

AbstractThe UK has introduced legislation that requires net-zero greenhouse gas emissions to be achieved by 2050. Improving the energy efficiency of homes is a key objective to help reach this target, and the UK government’s Clean Growth Strategy aims to get many homes up to an Energy Performance Certificate (EPC) Band of C by 2035. The relationship between home energy-efficiency and occupant health and wellbeing remains an area of ongoing research. This paper explores the nexus between home energy efficiency, energy consumption and self-reported health—an indicator of the general health and wellbeing of the population. We focus on Greater London through secondary data analysis. Energy-efficiency ratings and air infiltration rates of dwellings, derived from EPCs, were aggregated and matched to local area self-reported health and energy consumption data obtained from the Greater London Authority’s (GLA) Lower Layer Super Output Area (LSOA) Atlas database. Our regression model indicates that improving the energy efficiency (SAP) rating by 10 points for a typical home may reduce household gas consumption by around 7% (95% CIs: 2%, 14%). Beta regression finds a positive, but not statistically significant association between median SAP rating and the proportion of the population reporting ‘good or very good’ health when considering all Greater London LSOAs (z score = 0.60, p value = 0.55). A statistically significant positive association is observed however when repeating the analysis for the lowest income quartile LSOAs (z score = 2.03, p value = 0.04). This indicates that the least well-off may benefit most from home energy efficiency programs. A statistically significant positive association is also observed for the relationship between self-reported health and air infiltration rates (z score = 2.62, p value = 0.01). The findings support existing evidence for the predominantly naturally ventilated UK housing stock, suggesting that home energy efficiency measures provide a co-benefit for occupant health provided that adequate air exchange is maintained.

Comparison of Blower Door and Tracer Gas Testing Methods for Determination of Air Infiltration Rates Through Building Envelopes at Normal Operating Conditions

2011 ◽  
Author(s):  
Tapan Patel ◽  
Constandinos Mitsingas ◽  
James P. Miller ◽  
Ty A. Newell
Keyword(s):  
Building Envelope ◽  
Leakage Rate ◽  
Operating Conditions ◽  
Air Leakage ◽  
Tracer Gas ◽  
Annual Average ◽  
Normal Operating ◽  
Infiltration Rates ◽  
Air Infiltration ◽  
Air Leakage Rate

Tracer gas and blower door testing are two widely used methods to determine the rate of air infiltration through a building envelope. Blower door testing is performed at elevated pressure differentials across the building envelope whereas tracer gas testing is conducted at near zero differential pressures, better reflecting the air leakage rate at near normal building operating conditions. The primary objective of this study was to determine whether extrapolation of blower door test data to normal building operating conditions provides a good estimate of annual average air infiltration at those conditions. Two methods were used to extrapolate the data and were then compared to the baseline tracer gas tests. A secondary objective was to determine the ventilation rate of a residential facility using tracer gas tests. Tracer gas testing seems to be more reliable in determining the air leakage rate at normal operating pressures, but is sensitive to the tracer gas and ambient weather conditions. Regardless, for the subject facility, the ACH50/20 rule and Sherman’s ACH50/N correlation, extrapolated from the blower door tests, are within 6%–33% and 4%–38% of the tracer gas results, respectively. However, these errors are dependent on the assumptions used. Nevertheless, it appears that simple blower door testing can provide a reasonable measure of a building’s annual average air infiltration rate regardless of ambient conditions, whereas the more expensive and complex tracer gas tests may better reflect seasonal variations in air infiltration rates.

scholarly journals Air Infiltration Rates in Pre- and Post-Weatherized Houses

1985 ◽  
Vol 35 (5) ◽  
pp. 545-551 ◽  
Author(s):  
Brian Lamb ◽  
Hal Westberg ◽  
Pat Bryant ◽  
Janet Dean ◽  
Steve Mullins
Keyword(s):  
Infiltration Rates ◽  
Air Infiltration

On-site measurement of winter indoor environment and air infiltration in an airport terminal

2018 ◽  
Vol 28 (4) ◽  
pp. 564-578 ◽  
Author(s):  
Xiaochen Liu ◽  
Xiaohua Liu ◽  
Tao Zhang ◽  
Bowen Guan
Keyword(s):  
Energy Consumption ◽  
Thermal Environment ◽  
Space Heating ◽  
Large Space ◽  
Heating Systems ◽  
Indoor Thermal Environment ◽  
Infiltration Rates ◽  
Air Infiltration ◽  
Airport Terminal ◽  
Airport Terminals

Currently, many airports in China are being built or retrofitted. Reducing energy consumption in airport terminals is of the utmost urgency. This paper describes on-site measurements of indoor thermal environment and air infiltration of a hub airport in winter in southwest China. Air velocity measurements with air volume balance check and thermal balance check were applied to assess air infiltration rates in terminal buildings. In unsecured halls, air infiltration rates were 0.61 air change per hour (ACH) (6.6 m3/(h m2)) and 0.28 ACH (3.0 m3/(h m2)) when space heating was on and off, respectively; while in secured piers, those two air infiltration rates were 0.42 ACH (2.6 m3/(h m2)) and 0.24 ACH (1.5 m3/(h m2)). Air infiltration consumed 66–92% of heat supplied by space heating systems, showing that winter air infiltration significantly affects indoor thermal environment and energy consumption in terminal buildings where air flows out through the doors of service walkways and open skylights on the roof. Furthermore, influences of building characteristics, space heating systems and outdoor temperatures on winter air infiltration in large space buildings were analysed. This research helps to clarify the key issues influencing indoor thermal environment and proposes solutions for energy saving in terminal buildings.

Swine Finishing Room Air Infiltration: Part 2. Infiltration as Affected by Room Characteristics

2018 ◽  
Vol 34 (4) ◽  
pp. 735-745
Author(s):  
Harishchandra T Jadhav ◽  
Steven J Hoff ◽  
Jay D Harmon ◽  
Daniel S Andersen
Keyword(s):  
Linear Regression ◽  
Power Law ◽  
Infiltration Rate ◽  
The United States ◽  
Design Criterion ◽  
Large Variability ◽  
Infiltration Rates ◽  
Air Infiltration ◽  
Ceiling Height ◽  
The Relationship

Abstract. Data collected on 17 swine finishing rooms from the Midwest region of the United States was used to study the relationship between infiltration rate and selected room characteristics. Effect of individual room characteristics on room infiltration rate were tested by simple linear regression (SLR) while multiple linear regression (MLR) was used to develop models for improved prediction. SLR results revealed that the total (It) and other (Io; non-curtain/fan locations) swine finishing room infiltration rates were inversely related to room width and directly related to room length and ceiling height. As expected, rooms with higher curtain end pocket overlap, curtain closure overlap distance, and in excellent condition had reduced curtain infiltration (Ic). To reduce fan infiltration (If), fan and pump-out cover perimeter and fan area should be minimized. Power law equations fitted for groups of rooms were found ineffective in accounting for the large variability in infiltration rates of swine finishing rooms as compared to MLR models. MLR models developed for It and Io prediction at 10, 20, and 30 Pa pressure differences were found to improve the prediction over power law models for groups of rooms. At 20 Pa, prediction differences compared with individual room measurements for It rate using the suggested MLR model, as compared to power law models for groups of rooms, were less by at least 61%; whereas, in the case of Io rate, prediction differences compared with individual room measurements were less by at least 49%. Recommendations made in this article, with respect to the relationship between a particular room characteristic and room infiltration rate, could be used as guiding principles along with other design criterion to reduce infiltration rates in remodeled and new swine finishing rooms. Keywords: Infiltration, Swine finishing rooms, Ventilation.

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